Portable door alarm



July 12, 1966 J. v. KARDEL 3,261,010

PORTABLE DOOR ALARM Filed Nov. 26, 1963 2 Sheets-Sheet l O 'ILEE;

/2 40 4f 4a- 4a 44 I J4 A TTOR/VEYS July 12, 1966 J. v. KARDEL PORTABLE DOOR ALARM 2. Sheets-Sheet 2 Filed Nov. 26, 1963 INVENTOR l% [4/ Z T XIVA YS United States Patent 3,261,010 PORTABLE DOOR ALARM John V. Kardel, 906 St. Johns, Wyandotte, Micl Filed Nov. 26, 1963, Ser. No. 326,160 16 Claims. (Cl. 340-2S3) The present invention relates to an improved portable door alarm for removable application to the door of a room in a hotel, motel or residence for the purpose of giving an alarm in the event of an attempt at unauthorized access to the room from the outside thereof.

In a preferred embodiment of the invention, the alarm is given by an audible signal, although this signal may be, with a slight change in the wiring of the device, a visible, or a simultaneously audible and visible alarm.

The invention also contemplates the use of the device, when not applied to the door, as a handy electrical flashlight.

It is an object of the invention to provide an alarm for this purpose which is very compact and light in weight, as well as being entirely self-contained and free from reliance on an external source to power its alarm means. Thus, in accordance with the invention, the device includes, in a preferred form, a simple though reliable type of clamp device, by which the alarm may be adjusted for application to and at the top of doors of different thickness; and the invention includes provisions for enabling the retraction or collapse of such clamp means, when the alarm is not in use, within the external outline of the alarm structure as a whole, so that the device may be readily transported in a traveling bag, or used as a flashlight.

Furthcr in accordance with the invention, the alarm, as hung onto the top of a door through the agency of the clamp means referred to, comprises a switch control arm or finger which in that position projects upwardly of the door across the adjacent rface of the door frame lintel, being held by the lintel, when the door is closed, in a position to open the lamp and horn circuitry of the device, and to swing outwardly when the door is opened to close the electrical circuits at this master switch. In accordance with the improvement of the invention, the switch control arm or finger is also adapted to be swung about apivot on the device to an inoperative o-r retracted position, in which it, like the clamp device, lies fully within the external outline of the alarm, presenting no projecting portion apt to become snagged in a traveling case. Still further in accordance with the invention, the switch arm in the last named, retracted position thereof opens the horn and lamp circuitry of the device.

While in the illustrated embodiment the alarm is removed from the door to swing the control arm to the retracted position, it will be apparent to those skilled in the art that a slight modification will enable the retraction of the arm as described without removal of the device from the door. In either event, the alarm incorporates secondary selective switch means enabling the device to be set to produce an audible alarm signal upon an unauthorized attempt to .gain access to the room, or to be set for manual operation as a handy electrical flashlight, with the device removed from the door and the master control arm swung to its retracted position.

More specifically, provide switch and swinging arm control means of the sort described, in which the switch control arm, in maintaining the switch open when the alarm is attached to the door, by engagement with the door lintel as mentioned above, is automatically urged by a resilient contact of the switch to a position permitting that contact to close the switch when the door is opened and moves away from or inwardly of the door lintel; and in which the switch conit is an object of the invention to v 3,261,010 Patented July 12, 1966 trol arm occupies an over-center position in its retracted condition, insuring that the resilient contact will open the master switch in this position of the arm. As herein shown, switch bias is provided solely by a resilient contactor of the switch, although it is contemplated that this action may be supplemented by additional spring means.

Generally speaking it is an object of the invention to provide an audible and/ or visible signal emitting alarm of the above character which is simple and inexpensive in its parts, capable of being merchandised at an attractive figure, compact and easily mounted and dismounted from its positon in use, and without marring or disfiguring the door structure with which it is associated. As.

mounted to the door, the alarm is proof against tampering from the exterior, since its master switch control arm is shielded against external access by the existing stop molding of the door structure.

The foregoing as well as other objects will become more apparent as this description proceeds, especially when considered in connection with the accompanying drawings illustrating the invention, wherein:

FIG. 1 is a perspective view of the improved alarm of the invention, showing the samewith its adjustable door clamp and switch control arm means operatively positioned prior to application of the device to a door;

FIG. 2 is a side elevational view depicting the retracted or inoperative position of the clamp and switch control arm means referred to within the overall top, bottom and side confines of the alarm;

FIG. 3 is a view in transverse vertical section along line 3-3 of FIG. 4;

FIG. 4 is a view in vertical section along line 4-4 of FIG. 3, showing the alarm device as ope-ratively applied to a door;

FIG. 5 is a schematic view illustrating three different positions of the switch control arm of the device, i.e., with the arm held in operative position when the door is closed, thus opening the master electrical contact of the device; in a slightly cocked position as the door is moved away from the door frame and lintel, thus closing the master circuit; and in an operatively retracted or collapsed position to open the circuitry;

FIG. 6 is a simple schematic wiring diagram of the basic operating components of the alarm; and

FIG. 7 is an alternative wiring diagram contemplated by the invention.

The portable alarm device of the invention is generally designated by the reference numeral 10. It comprises an external housing or casing 11 which may be molded inexpensivcly of a suitable plastic composition, the casing 11 being shown (FIG. 3) as including parallel upright side walls 12, 13, a top panel 14, a bottom panel 15, a front or door-engaging panel 16 and a rear of room-facing panel 17 The bottom panel 15 is provided with a central rectangular aperture through which the illumination of an alarm lamp 19 may pass; and the bead or flange 20 of the reflector of this lamp, together with a transparent window 21, are received in parallel ways adjacent the bottom of the side panels 12, 13, so that the window 21 may be removed if needed for replacement of the bulb 22 of the lamp. A central terminal of bulb 22 makes electrical contact with a spring terminal 23 which has an electrical series connection with a pair of dry cell batteries 24 (FIG. 4) housed in a small battery container 25 suitably mounted within casing 11. Suitable terminal buss strip means 26 is employed to series-connect the batteries in a manner well known in miniature radios and the like.

A simple type of selector switch 28 is also fixedly mounted within the alarm casing 11, as to the side wall 12 of the latter, and the nature, function and wiring of the switch 28 will be hereinafter referred to.

Also appropriately mounted fixedly within the casing 11 is an audible alarm or horn 29; and this horn is, like the alarm 19, also adapted to be electrically energized through the circuit provisions hereinafter described. The rear or inwardly facing panel 17 of casing 11 will be provided with an appropriate opening for easy hearing by the room occupant.

A master control switch, generally designated by the reference numeral 30 is fixedly mounted by means of a small bracket 31 on the forward or door facing panel 16 of casing 11. This switch comprises the relatively fixed and movable contacts 32, 33 respectively, contact 33 being in the form of an elongated conducting leaf spring. Contact 33 is operated, as between two open positions and an intermediate closed position (FIG. by a master control arm or finger 35, best shown in FIGS. 3 and 4. Arm 35 is of generally L-shaped outline in side elevation (FIG. 4), and is provided with a thickened cam portion 36 adjacent the junction of its arms, at which portion the arm 35 is pivotally mounted within the casing 11. For this purpose a pivot pin 37 is employed, one end of the pin being journaled in an opening 38 adjacent the top of easing wall 12, the other end of the arm being journaled in a suitable depending bracket 39 \formed integral with casing top panel 14.

The upper end of master switch control arm 35 extends through a slot 40 formed in the top panel 14 and also extending downwardly at 41 (FIG. 1) in the forward or outer panel 16 of the casing; and further reference will be made to this slotting arrangement.

master control arm or finger 35.

Thus, as best shown in FIG. 1, the outwardly or forwardly facing panel 16 is formed to provide a transversely extending guide bracket 43 in the form of an inverted U of slight height; and for coaction with this bracket, the door clamp, as generally designated 44, comprises a pair of parallel spring arms 45 and a clamping foot 46 at 90 to these arms. This entire clamp structure may be formed of a sheet metal stamping.

More specifically, the clamping foot 46 is formed to provide a pair of friction nibs 47, and the arms 45 are formed to provide longitudinally serrated jaw edges at 48, the arms terminating in outwardly offset finger pieces 49 having integral 90 ears 50 for the manipulation of clamp 44. Thus it is seen, reference being had to FIGS. 1 and 4, that the arms 45 may be compressed toward one upon the arms are released and their serrations 48 engage outwardly against the sides of bracket 43 to hold the clamp 44 in place to rigidly support casing 11 on the top of the door. In this position, the usual stop molding M of the door frame structure blocks access to the master switch arm 35 from the exterior, rendering the alarm tamperproof in this respect.

If desired, the casing panel 16 may also be equipped with a fixed plate 51 which is slit and offset to provide a spring clamp tongue 52. Indeed, in some embodiments it may be desirable to omit the adjustable clamping features, employing a fixed clamp in association with the spring tongue 52, particularly in instances where a uniform door thickness can be relied on.

In regard to the actual embodiment illustrated, when it is desired, upon removal of alarm 10 from the door,

to place the same in condition for traveling or storage, the clamp arms 45 are compressed at their finger ears 5th to permit the entire clamp 44 to be shifted outwardly or forwardly beneath fixed bracket 43, whereupon it is swung downwardly into parallel engagement with the casing panel 16. As it goes into this position the ears 50 will be received in accommodation recesses 54 within the respective upright side walls 12, 13; and the friction nibs 47 formed in the clamp foot 46 will snap into registering small recesses 55 formed in the bottom panel 15 (FIGS. 1 and 2). Thus the entire clamp is brought within the wall confines of casing 11, as best appears in FIG. 2. The proportioning of the parts is such that the spring tongue 52 will be compressed by the clamp 44 when the latter is swung to the retracted or compacted position of FIG. 2, either by the weight of the clamp or by the snap locking effect of the nibs 47 in recesses 55.

By the same token, and as also shown in FIG. 2, the master control arm 35 may be swung through the recesses 40, 41 of casing 11 to a position paralleling the wall panel 16, with a thickened, linte l-engaging end portion 56 of the control arm received in an accommodation recess 57 of casing 11, again with the control arm brought completely within the contour outline Otf the casing for compactness in transportation or storage.

Now referring to FIG. 5 of the drawings, the cam formation 36 on master control arm 35, which may be molded as an integral part of the latter from a suitable insulating plastic composition, is shown in a generally elliptical, though pointed end outline. Referring to FIG. 4 in conjunction with FIG. 5, it is seen that in the operative position of the alarm 10 as applied to the door D with the control arm of finger held upright in engagement with the lintel facing F, one lobe of the cam 36 engages spring conducting contact 33 (to the left in FIG. 5) and holds the same in open relation to the fixed contact 32. In doing this, spring contact 33 of course acts to urge switch control arm 35 clockwise about its pivot pin 37, as viewed in FIGS. 4 and 5. However, upon opening of the door D the arm 35 cocks outwardly under this spring bias to the position shown in dotted line in FIG. 4 and in the center sketch of FIG. 5. Contact 33 engages fixed contact 32 to complete a lamp energizing circuit at the master control switch 30. On the other hand, when alarm 10 is taken off the door and compacted by swinging arm or finger 35 further clockwise, as shown at the right of FIG. 5, the second pointed lobe of cam 36 engages spring contact 33 and opens the circuit at master switch 30. As indicated above, the bias exerted by spring contact 33 may, if desired or necessary, be supplemented by further spring means (not shown).

As also indicated above, the pivoting of the master switch arm 35 on the casing 11 may be such as to enable its swing inwardly, or counterclockwise as viewed in FIG. 5, to the master circuit-breaking position, rather than clockwise. This enables a de-energization of the master circuit without removing the alarm 10 from the door.

The selector switch 28 is shown in circuit with master switch 30, battery unit 24, lamp 19 and horn 29, in the simplified wiring diagram of FIG. 6. Switch 28 is scheis selectively engageable with contacts 59, 60 and 61 of the three position selector switch 58. The intermediate contact 60 is a dead one; while the contacts 59 and 61 are respectively wired to master figure, i.e., when the door is opened. If it is not desired to have both the audible and visible alarm, contactor 58 is placed on intermediate contact 60. This opens the circuit lamp 19, with the result that only an audible signal is produced by horn 29 when the door is opened and master switch 30 goes closed.

On the other hand, should it be desired to utilize the device as a flashlight, independently of master switch 30, and with the device removed from the door, the master switch is opened by swinging its control arm 35 to the retracted position of FIG. 2, or oppositely to a correspondingly retracted position, in which the cam 36 opens switch 30 (right-hand side of FIG, The selector switch contactor 58 is then manually engaged with contact 61 to complete a lamp energizing circuit alone, which may be opened and closed as the owner desires, in the manner in which one manipulates a conventional flashlight. When the device is returned to the door for use as an alarm, selector switch 28 will of course not be left with its contactor on the flashlight contact 61, so that the alarm is ready for use as soon as the master contact arm 35 is extended.

In the alternative wiring diagram of FIG. 7, the selector switch is designated 28', being shown as comprised of a wiper contact 63 on a pivoted conducting arm 64 which is electrically connected by a lead 65 to the spring contact 33 of master switch 30. Wiper contactor 63 is of a predetermined arcuate extent adapted to make conducting engagement with one or the other of two horn and lamp contacts or terminals 66, 67 respectively, to the exclusion of the other, or to simultaneously bridge and conductively engage both of the terminals 66, 67. The battery unit 24 is series circuit connected to the fixed master switch contact 32, and, in circuits parallel to one another, through the horn 29 and lamp 19 to the respective terminals 66, 67 of these signal devices.

Thus, as depicted in solid and dotted lines in FIG. 7, the wiper contactor 63 is in engagement with neither or the horn and lamp terminals 66, 67. It may be swung to engage only one or the other thereof, completing the electrical circuit through horn 29 or lamp 19, or vice versa. It may also be swung to a position conductively bridging terminals 66, 67, whereupon the horn and lamp will be simultaneously energized for a combined signal. It is possible also to use the alarm as a simple flashlight and/ or as an audible signal by appropriately manipulating the switch 28 with the master switch 30 in the closed condition.

The alarm is seen to be simple, inexpensive and reliable in operation, and very compact indeed. It may be quickly and easily set up and taken down to and from an operative condition, and with the parts retracted to the position of FIG. 2, it may be transported or stored in a very small space, or used as a hand flashlight.

What I claim as my invention is:

1. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to mount the same on one of said members, an electrically powered signal unit in said casing, means in said casing to provide an electrical circuit to control the energization of said signal unit, including a movable switch control element projecting externally of the casing for engagement with the other of said members in a manner to be moved upon said relative movement of the members, and a switch having contacts opened and closed respectively by said control element in first and second positions of the latter prior to and after said relative movement, said switch control element being movable to a further position in relatively retracted relation to said casing, and in a location in which the control element is not engageable by said other relatively movable member in which further position said element opens said contacts;

2. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to removably mount the same on one of said members, an electrically powered signal unit in said casing, means in said casing to provide an electrical circuit to control the energization of said signal unit, including a pivotally movable switch control element projecting externally of the casing for engagement w'th the other of said members in a manner tobe moved upon said relative movement of the members, and a switch having contactsopened and closed respectively by said control element in first and second positions or" the latter prior to and after said relative movement, said switch control element being swingable to a further position in relatively retracted relation to said casing and substantially within the external outline of the latter when the casing is removed from said one member, in which further position said element opens said contacts, said casing having a recess receiving said switch control element in said further retracted position of the latter.

3. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to removably mount the same on one of said members, an electrically powered signal unit in said casing, means in said casing to provide an electrical circuit to control the energization of said signal unit, including a pivotally movable switch control element projecting externally of the casing for engagement with the other of said members in a manner to be moved upon said relative movement of the members, and a switch having contacts opened and closed respectively by said control element in first and second positions of the latter prior to and after said relative movement, said switch control element being swingable to a further position in relatively retracted relation to said casing, in which further position said element opens said contacts, said control element having a formation thereon engageable with one of said contacts in said first and further positions of said element to positively open said switch.

4. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to removably mount the same on one of said members, an electrically powered signal unit in said casing, means in said casing to provide an electrical circuit to control the energization of said signal unit, including a pivotally movable switch control element projecting externally of the casing for engagement with the other of said members in a manner to be moved upon said relative movement of the members, and a switch having a resilient, relatively movable contact and a fixed contact, which contacts are open and closed respectively by said control element in first and second positions of the latter prior to and after said relative movement, said switch control element being swingable to a further position in relatively retracted relation to said casing, in which further position said elementopens said contacts, said control element having a cam formation thereon engageable with said resilient, relatively movable contact in said first and further positions of said element to positively open said switch, said resilient contact biasing said cam formation of said control element for movement of the latter from said first position to said second position and from said further position to said second position to respectively close and open said switch.

5. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to removably mount the same on one of said members, an electrically powered signal unit in said casing, means in said casing to provide an electrical circuit to control the energization of said signal unit, including a piovtally movable switch control element projecting externally of the casing for engagement with the other of said members in a manner to be move upon said relative movement of the members, and a switch having a resilient, relatively movable contact and a fixed contact, which contacts are opened and closed respectively by said control element in first and second positions of the latter prior to and after said relative movement, said switch control element being swingable to a further position in relatively retracted relation to said casing and substantially within the external outline of the latter when the casing is removed from said one member, in which further position said element opens said contacts, said control element having a cam formation thereon engageable with said resilient, relatively movable contact in said first and further positions of said element to open said switch, said resilient contact biasing said cam formation of said control element for movement of the latter from said first position to said second position and from said further position to said second position to respectively close and open said switch, said casing having a recess receiving said switch control element in said further, retracted position of the latter.

6. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to removably mount the same on one of said members including a clamp adjustably carried on said casing for movement to a position to engage and clamp to one of said relatively movable members and to a relatively retracted position in a substantially different angular relation to said clamping position in which said clamp is substantially within the external outline of the casing.

7. A portable device of the type described, comprising a casing having means to removably mount the same on a supporting member including a clamp adjustably carried on said casing for movement to a position to engage and clamp to said member, said clamp comprising a clamp element and a pair of springable arms connected to said clamp element, said casing having a bracket portion releasably engageable by said arms to hold said clamp element in a selected predetermined adjusted position on the casing to engage and clamp the casing to said memher, said arms of said clamp element being operatively connected to said bracket portion to swing relative to the latter into a retracted position against said casing.

8. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to removably mount the same on one of said members including a clamp adjustably carried on said casing for movement to a postion to engage and clamp to one of said relatively movable members, said clamp comprising a clamp element and a pair of springable arms connected to said clamp element, said casing having a bracket portion releasably engageable by said arms to hold said clamp element in a selected predetermined adjusted position on the casing to engage and clamp the casing to one of said relatively movable members, said arms of said clamp element being operatively connected to said bracket portion to swing relative to the latter into a retracted position against said casing.

9. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to removably mount the same on one of said members, an electrical battery-powered signal unit in said casing, means in said casing to provide an electrical circuit to control the energization of said signal unit, including a movable switch control element projecting externally of the casing for engagement with the other of said members so as to be moved upon said relative movement of the members, and a switch respectively opened and closed by said control element in first and second positions of the latter prior to and after said relative movement, said switch control element being movable to a further position in relatively retracted relation to said casing and substantially within the external outline of the latter, said mounting means of said casing comprising a clamp adjustably mounted on the latter for movement to a position to engage and clamp to one of said relatively movable members and to a relatively retracted position in which said clamp is substantially Within the external outline of the casing.

10. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to removably mount the same on one of said members, an electrical battery-powered signal unit in said casing, means in said casing to provide an electrical circuit to control the energization of said signal unit, including a movable switch control element projecting externally of the casing for engagement with the other of said members so as to be moved upon said relative movement of the members, and a switch respectively opened and closed by said control element in first and second positions of the latter prior to and after said relative movement, said switch control element being movable to a further position in relatively retracted relation to said casing and substantially within the external outline of the latter, in which last named position said element opens said switch, said control element being operable on said switch in said further position of said element to open the switch, said mounting means of said casing comprising a clamp adjustably mounted on the latter for movement to a position to engage and clamp to one of said relatively movable members and to a relatively retracted position in which said clamp is substantially within the external outline of the casing.

11. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to removably mount the same on one of said members, an electrical battery-powered signal unit in said casing, means in said casing to provide an electrical circuit to control the energization of said signal unit, including a movable switch control element projecting externally of the casing for engagement with the other of said members so as to be moved upon said relative movement of the members, and a switch respectively opened and closed by said control element in first and second positions of the latter prior to and after said relative movement, said switch control element being movable to a further position in relatively retracted relation to said casing and substantially within the external outline of the latter, said mounting means of said casing comprising a clamp adjustably mounted on the latter for movement to a position to engage and clamp to one of said relatively movable members and to a relatively retracted position in which said clamp is substantially within the external outline of the casing, said clamp comprising a clamp element and a pair of springable arms connected to said clamp element, said casing having a bracket portion engageable by said arms to hold said clamp element in predetermined position to engage and clamp to one of said relatively movable members.

12. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to removably mount the same on one of said members, an electrical battery-powered signal unit in said casing, means in said casing to provide an electrical circuit to control the energization of said signal unit, including a movable switch control element projecting externally of the casing for engagement with the other of said members so as to be moved upon said relative movement of the members, and a switch respectively opened and closed by said control element in first and second positions of the latter prior to and after said relative movement, said switch control element being movable to a further position in relatively retracted relation to said casing and substantially within the external outline of the latter, in which last named position said element opens said switch, said control element being operable on said switch in said further position of said element to open the switch, said mounting means of said casing comprising aclamp adjustably mounted on the latter for movement to a position to engage and clamp to one of said relatively movable members and to a relatively retracted position in which said clamp is substantially within the external outline of the casing, said clamp comprising a clamp element and a pair of springable arms connected to said clamp element, said casing having a bracket portion engageable by said arms to hold said clamp element in predetermined position to engage and clamp to one of said relatively movable members.

13. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to removably mount the same on one of said members, an electrical battery-powered signal unit in said casing, means in said casing to provide an electrical circuit to control the energization of said signal unit, including a movable switch control element projecting externally of the casing for engagement with the other of said members so as to be moved upon said relative movement ct" the members, and a switch respectively opened and closed by said control element in first and second positions of the latter prior to and after said relative movement, said switch control element being movable to a further position in relatively retracted relation to said casing and substantially within the external outline of the latter, in which last named position said element opens said switch, said control element being operable on said switch in said further position of said element to open the switch, said mounting means of said casing comprising a clamp adjustably mounted on the latter for movement to a position to engage and clamp to one of said relatively movable members and to a relatively retracted position in which said clamp is substantially within the external outline of the casing, said casing being recessed to receive said control element and said clamp in the retracted positions thereof.

14. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to mount the same on one of said members, an electrical batterypowered signal unit in said casing, and means in said casing to provide an electrical circuit to control the energization of said signal unit, including a movable switch control element projecting externally of the casing for engagement with the other of said members, thus to be moved upon said relative movement of the members, a master switch having contacts which are respectively opened and closed by said control element in first and second positions of the latter prior to and after said relative movement, said control element being movable to a further position to engage and positively open at least one of said contacts, and a manually operable selector switch having means electrically connecting the same to said signal unit to optionally control energization of the latter when said control element of said master switch is in said further position.

15. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to mount the same on one of said members, an electrical batterypowered signal unit in said casing, and means in said casing to provide an electrical circuit to control the energization of said signal unit, including a movable switch control element projecting externally of the casing for engagement with the other of said members, thus to be moved upon said relative movement of the members, a master switch having contacts which are respectively opened and closed by said control element in first and and second positions of the latter prior to and after said relative movement, said control element being movable to a further position to engage and positively open at least one of said contacts, said signal unit comprising audible and visible alarm emitting devices, and a manually operable selector switch having means electrically connecting the same to said devices to optionally control energization of the latter when said control element of said master switch is in said further position.

16. A portable alarm for application to one of a pair of relatively movable members to signal such relative movement, comprising a casing having means to mount the same on one of said members, an electrical batterypowered signal unit in said casing, and means in said casing to provide an electrical circuit to control the energization of said signal unit, including a movable switch control element projecting externally of the casing for engagement with the other of said members, thus to be moved upon said relative movement of the members, a master switch having contacts which are respectively opened and closed by said control element in first and and second positions of the latter prior to and after said relative movement, said control element being movable toa further position to engage and positively open at least one of said contacts, said signal unit comprising audible and visible alarm emitting devices, and a manually operable selector switch having means electrically connecting the same to said visible alarm device of said signal unit to optionally control energization of the last named device when said control element of said master switch is in said further position.

References Cited by the Examiner UNITED STATES PATENTS 635,100 10/1899 Huebel 248-205 1,146,883 7/1915 Jones 340-274 2,259,696 10/1941 Hulst 340-283 2,446,217 8/ 1948 Drufiel.

2,624,792 1/ 1953 Fruh 340-276 X 2,816,280 12/ 1957 Detweiler. 2,826,656 3/1958 Gordon 340-283 X 2,866,181 12/1958 Gordon 340-283 X 2,943,308 6/1960 Westphal 340-276 3,011,163 11/1961 Britt 340-274 3,056,954 10/1962 Jorritsma 340-321 FOREIGN PATENTS 681,165 10/1952 England.

NEIL C. READ, Primary Examiner.

R. M. GOLDMAN, Assistant Examiner. 

1. A PORTABLE ALARM FOR APPLICATION TO ONE OF A PAIR OF RELATIVELY MOVABLE MEMBERS TO SIGNAL SUCH RELATIVE MOVEMENT, COMPRISING A CASING HAVING MEANS TO MOUNT THE SAME ON ONE OF SAID MEMBERS, AN ELECTRICALLY POWERED SIGNAL UNIT IN SAID CASING, MEANS IN SAID CASING TO PROVIDE AN ELECTRICAL CIRCUIT TO CONTROL THE ENERGIZATION OF SAID SIGNAL UNIT, INCLUDING A MOVABLE SWITCH CONTROL ELEMENT PROJECTING EXTERNALLY OF THE CASING FOR ENGAGEMENT WITH THE OTHER OF SAID MEMBERS IN A MANNER TO BE MOVED UPON SAID RELATIVE MOVEMENT OF THE MEMBERS, AND A SWITCH HAVING CONTACTS OPENED AND CLOSED RESPECTIVELY BY SAID CONTROL ELEMENT IN FIRST AND SECOND POSITIONS OF THE LATTER PRIOR TO AND AFTER SAID RELATIVE MOVEMENT, SAID SWITCH CONTROL ELEMENT BEING MOVABLE TO A FURTHER POSITION IN RELATIVELY RETRACTED RELATION TO SAID CASING, AND IN A LOCATION IN WHICH THE CONTROL ELEMENT IS NOT ENGAGEABLE BY SAID OTHER RELATIVELY MOVABLE MEMBER IN WHICH FURTHER POSITION SAID ELEMENT OPENS SAID CONTACTS.
 9. A PORTABLE ALARM FOR APPLICATION TO ONE OF A PAIR OF RELATIVELY MOVABLE MEMBERS TO SIGNAL SUCH RELATIVE MOVEMENT, COMPRISING A CASING HAVING MEANS TO REMOVABLY MOUNT THE SAME ON ONE OF SAID MEMBERS, AN ELECTRI- 